


Breeding Season

by thursdayshunter



Category: Supernatural
Genre: Anal Plug, Angst, Biting, Bottom Castiel, Breeder!Cas, Breeding, Creature Dean, DeanCas - Freeform, Double Anal Penetration, Double Penetration, Hunter Castiel, M/M, Mating, Monster!Dean, Mpreg, Naga, Non-Consensual Body Modification, Poison, Rape, Rough Sex, Top Dean, Violence, Violent Sex, mentions of consuming humans, pregnant!cas, temporary paralysis
Language: English
Status: Completed
Published: 2014-10-09
Updated: 2014-10-09
Packaged: 2018-02-20 13:38:53
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 4,602
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2430821
Author URL: https://archiveofourown.org/users/thursdayshunter/pseuds/thursdayshunter
Summary: <blockquote class="userstuff">
              <p>Something coiled like a great serpent and his lungs froze in shock. Seconds seemed like hours as he reached for his gun but the thing in the dark shot out and something sank into his neck. The creature retreated as Castiel’s hand closed around his gun. He struggled to get his fingers to work so he could remove the safety even as his other hand covered two punctures.</p><p>Filled for SPNKink-Meme</p>
            </blockquote>





	Breeding Season

**Author's Note:**

> READ THE TAGS!! This is a darker themed fic.
> 
> Prompt description at bottom.

Castiel glanced into the mouth of the cave looking for any movement. He had yet to find the supposed monster that those in the nearby town had been claiming lived near them for years. Every single place he had checked in the surrounding area turned up empty.

No sign of anything supernatural.

A sigh escaped as he clicked his safety and shoved his gun in the back of his pants. He would check this last cave, drag himself back to his room and take a long, hot shower to get all the dirt and grime off before eating two cheeseburgers.

He’d _earned_ it.

His footsteps echoed as he walked further into the cave. “Nothing.” He muttered to himself as he continued forward getting deeper inside.

It came out of the dark.

Something coiled like a great serpent and his lungs froze in shock. Seconds seemed like hours as he reached for his gun but the thing in the dark shot out and something sank into his neck. The creature retreated as Castiel’s hand closed around his gun. He struggled to get his fingers to work so he could remove the safety even as his other hand covered two punctures.

“Shit.” He swallowed as something cool started to slowly spread through his body, traveling through his veins and stealing his ability to keep his feet.

Castiel took two stumbling steps backwards when his gun slipped from his shaking hand. His breathing increased as cold sank into his bones and he had to brace his hand against the damp cave wall.

He could only watch in horror as the creature that had attacked moved from the shadows it had retreated to. It looked to be half man and half serpent. The eyes, which were fixed on him, glowed a poisonous green and its lips were curled in a pleased smile.

Fangs were visible when it opened its mouth and a language he’d never heard filtered out into the cave. There was an undertone of hisses to the words but Castiel couldn’t focus on that as his legs slowly gave out.

He felt sluggish and his mind seemed almost fuzzy when he tried to think beyond the situation.

The creature slithered closer and before Castiel’s eyes he watched as the creature started to shift until something resembling a man stood before him completely naked with noticeable green scales. Looking at it now Castiel finally noticed them.

It had two cocks where a normal man would only have one.

Castiel struggled to think back to the creature’s previous state and he wondered if its reproductive organs had been protected. _They aren’t anymore_ his mind thought sardonically trying to stay away from the horror of what the creature was going to do to him.

A few more steps brought it right to him and a hand reached out to touch him. It moved over his face and up to his hair to yank his head to the side for its gaze. Castiel could feel its breath near him and then a long tongue was dragging over the place it had _bit_ him.

There was something like a pleased sound as it drew back and stared at him with a predatory look in its poisonous gaze. “Please.” His voice sounded weak to his own ears but Castiel was going to do everything in his power to get out of here. He couldn’t die like this. “Please let me go.”

How many others had begged the creature over the years?

All those missing had never returned and a glance behind the creature where he had yet to look revealed shadowed shapes. Some of them looked as though they could be bones and he felt his breathing picking up.

The creature said something else as it started to lay him down while keeping its eyes on him. They seemed to move over every inch of him and Castiel shivered. He tried moving his legs but the movement took too much out of him.

It had to have injected him with some kind of paralytic.

Castiel groaned when his back met the hard floor of the cave but his attention was quickly diverted when it started using some kind of makeshift blade to cut through his clothing. Each move was deliberate as it cut through his layers so his bare chest was exposed to its gaze. The material of his shirts was no longer shielding him.

A cool hand pressed against his sternum before trailing down to his pants. “No.” Castiel tried to push it away but his hands felt like rubber and the creature easily pushed them to the side. It said something else and tsked at him.

His pants took longer for it to remove but it was more than obvious it had experience with removing clothing. There were more pleased sounds as it finished with his pants and it idly touched his soft cock.

“Please let me go.” He tried again and his voice was shaking in fear but if anything the creature’s interest was only increasing. A glance at its cocks revealed they were harder and liquid was beading at the tips.

This close he could see how long and thick they were, something on a normal man that would have been very impressive, and he was terrified. It couldn’t be doing what he was thinking. The creature must just get off on the terror of its victims before it ate them.

Suddenly its hands grabbed onto him and hauled him up as though he weighed nothing. Castiel could feel it moving him along further into the cave until they reached a huge chamber. Inside there were flames along the walls, bones discarded off to the side and something that kind of reminded him of a nest.

The creature took him in its direction and laid him out on his belly with another pleased sound. Its hands moved down his shoulders, along his sides and over the swell of his ass to spread his cheeks apart.

A sob tore its way out of his throat. “Don’t. Please don’t.” it was pointless since the creature didn’t seem to speak his language and he could feel its breath against his skin. The long tongue moved over his hole and he started violently shaking.

Whatever the creature had injected him with prevented him from putting up much of a struggle and his heart was hammering in his chest at the realization. There was nothing he could do to stop this creature from doing what it wanted.

“Breed.” The word was murmured and it held that same hissing quality but Castiel recognized it. He could hear it repeating the word several more times in various forms before that long tongue was slipping inside him. The creature kept it up before retreating with another pleased hiss.

It withdrew for a moment while Castiel lay there trying to hold back the terror. His breathing hitched and he wished for his gun. He wanted to empty the entire clip into the creature and then he wanted to empty another clip into it until it was unrecognizable.

He should have listened to his brother. Taking hunts on his own was stupid and no one knew he was even here. There was no back-up.

The creature came back but instead of a tongue pushing inside him it was slick fingers. They pumped inside his body and forced him to widen to accommodate them. Castiel whimpered at the painful stretch and how they pressed against his insides. A few moments of that and the creature was adding more fingers still keeping up the thrusting motion with them.

“Breed.” It spoke again but this time its voice had deepened and the lust was more than evident.

Castiel wished he couldn’t understand it or that the poison running through his veins would have stolen his consciousness. He didn’t want to be aware, to be trapped inside his own body, while it used him.

It had four fingers in him, fucking them in and out, as its heavy breathing sounded in the cave. Castiel could feel tears running down his cheeks at the pain and soreness in his ass. Then as suddenly as the fingers had first come they were gone and the creature was shifting.

The pressure at his hole had him slamming his eyes shut. He could feel how it was pushing _both_ of its cocks into him. Both thick cocks were sinking into him even as his ass tightened up and he whimpered at the unimaginable pain the stretch was sending through him.

He had never taken more than one cock in his years of being with men.

It was wave after wave of pain as the creature pressed over him and its heavy breathing ghosted along his sweat covered skin. “Breed.” Its mouth pressed against him and it started to rut against his ass in an effort to get as deep as possible.

Castiel wasn’t sure if he had blacked out or blocked it but when he became aware the creature was violently fucking into him with grunts and pleased hissing words that Castiel had given up trying to understand.

Occasionally he would catch _breed_ while it rammed into him with both cocks. His body was sore and ached, he felt as though he was being split in two, but the creature was far too lost in its quest to fuck him.

He cried out when it slammed into him in a particularly deep thrust and those cocks went farther than was comfortable. Each snap of its hips had the slap of skin against skin echoing in the cave. The filthy sound was mixing with the wet sound of the cocks moving through whatever the creature had used to slick its way, Castiel’s hitching sobs and the creature’s own grunts of pleasure.

Its motions became wild and even more vicious as it got closer and closing until Castiel felt it seize against him. There was a rough sound and suddenly Castiel could _feel_ its semen flooding his ass.

The creature’s release shot out in a thick, hard stream that had Castiel shoving his face into the creature’s nest and shuddering in disgust. He wanted it out but instead the creature rocked against his protesting body with soft grunts. “Breed.” It mumbled against him and fell asleep on top of him just like that with both cocks still buried inside him.

Castiel tried again to free himself but his limbs wouldn’t work and he was in so much pain he wasn’t sure he’d even get far in the unlikely chance that he found the correct tunnel to get back outside.

* * *

Dean slowly opened his eyes with a pleased smile on his features. He could see the mate he’d chosen for the breeding season laying under him, still tight around his cocks, as the human slept off their first mating.

He knew it took several matings before the human’s body could adapt and he would be able to successfully breed him. It was one of the problems with mating with a human but the offspring produced were always smart and strong.

It was only right that he give his offspring the best chance and breeding with a strong human gave them that advantage. He slowly touched the place on the human’s neck he’d bitten and gave a pleased sound.

The poison’s effects didn’t typically wear off until the next day and he could easily bite the human again. Hunting down his chosen breeding partner got tiresome and he’d rather use that energy to hunt meals.

He rotated his hips and smiled wider as the action stirred his mating drive. Dean could feel his cocks hardening and preparing for another breeding. Lazily he rocked against the human’s ass, the swell of the human’s cheeks filled him with arousal, as he looked over his new human’s body.

Dean had thought he would have to venture out to find a new mate for the season but something must have drawn this human to his cave. The gun hinted at a hunter but Dean thought it could have been the human trying to protect himself from others in the forest.

As it was most stayed away from the cave and usually it was only the younger humans, right at the perfect age for breeding, that ventured inside. A few times they had been younger, clearly lost or had wandered from the camp grounds, but he had still bred them regardless. His species was capable of it and the change to their bodies took just as easily as it did with the older humans he bred. Those humans never made it beyond one mating season but at least they were enjoyable to breed and still produced healthy offspring. He couldn't always be picky when mating season arrived.

The younger ones, new to adulthood, typically came from curiosity or for shelter. Usually his best chance was on a rainy day when one had been caught outside and was seeking cover. The ones a little younger he typically found when the sun started to fade and they couldn't find their way back.

He continued to idly rock forward and moaned when his motions started to send pleasure through him. Dean drew back before burying himself back inside the human’s tight hole with a hiss. It clenched around him tightly, as though trying to milk him and ensure successful breeding, as a whimper escaped.

Dean didn’t understand why humans fought the breeding process. He was a strong mate and he was very thorough when he bred them. The offspring were always strong, successful and if the human survived birthing his children he was more than happy to provide them with more.

Part of him wondered if he’d get more than one breeding season out of his current mate. The sounds the human made and his looks were enjoyable. It was the kind of mate Dean would enjoy breeding multiple times. He was sure offspring from this human would be strong and smart. They would no doubt be successful in finding a home, hunting and producing their own offspring.

There was a groan and Dean could feel the human struggling to awareness. He released a soft hum to let the human know he was pleased as he reached up to grip the human so he could start thrusting harder to begin mating once more.

His body sang with each snap of his hips and Dean mourned the fact that it was hard to mate with humans in his true form. He preferred coiling his tail with a mate while he bred them but his human form had its uses.

He could enjoy pinning a squirming body down and pounding into it. He could feel himself moving through his own seed and knew he was getting closer towards a successful breeding. “ _Good breeder_.” He praised as his cocks worked inside the human’s hole at an increasing pace.

Dean couldn’t wait to see the offspring this human would carry. He could already imagine how the human would swell with them, evidence of Dean’s virility, until the birthing day came. His offspring would be starving and Dean loved hunting for them. He loved watching them learning the use of their poisons, how to use both of their forms and the sated looks on their little faces when they finished a meal.

He would get a little time with them before they would grow too big and seek their own nests. Some would die and others would flourish. It was his responsibility to continue mating and breeding with others to produce as many successful offspring as possible.

Another whimper escaped the human and Dean could feel him struggling. Dean started moving harder, keeping his body braced for the best position, as he moved closer and closer to his release. He _needed_ to make sure the change took effect soon and then he could completely focus on breeding.

He was a good mate.

“ _Our offspring will be strong. They will be smart._ ” He assured the human. A sigh escaped when the human’s hole tightened around him. He loved how tight humans were and how they felt around his cocks.

It filled him with a blissful feeling and warmed him.

The human spoke, that silly language Dean rarely bothered using as he preferred his own, saying something about stopping.

That was ridiculous!

Stopping would slow down the change and breeding season was about mating. If he stopped it would stop their mating and he couldn’t risk that.

Dean tugged on the human’s hair in reprimand and turned his attention to thrusting inside tight, heat once more. His eyes hooded in pleasure and pressure started to push against his spine. He was close. Very close and the very thought had his thrusts turning wild.

Finally his cocks were pumping his release inside the human. He knew a few more matings and the human would be receptive for a proper breeding.

He stroked through the human’s damp hair, offering hissed praises, as his cocks emptied their load inside. This time instead of falling asleep he pulled out and rose to his feet. He felt warm and sated as he went to get the _plug_ another of his kind had suggested for breeding humans.

It was large and Dean had specifically chosen this one on one of his few trips into town as it kept his mate open wide enough while keeping his seed inside. He enjoyed the fact that it allowed him to push both of his cocks right back into his mate without having to deal with _preparation_.

He had learned his lesson after mating with a human without using the slick to open them. There had been blood and screaming. The change had not taken and he had killed the human for sustenance in his frustration. No offspring had come of that season and the failure still sat heavy in his stomach.

Dean crossed back to where the human was leaking out his seed and whimpering softly on his bed. Carefully he made sure to scoop up his seed and press it back inside, not wanting to let any of it go to waste, before he shoved the plug inside.

The action had the human whimpering again but Dean was too pleased at the sight of the plug keeping his seed inside to care.

He had enough time to hunt something for himself and to find something the human would digest since they refused to enjoy his kills. Dean moved through the cave before transforming back into his true shape.

A sigh of pleasure escaped as his tail coiled on the cave floor. He felt freer when he could easily move along the cool stones of his home and his speed was far greater. Being able to strike quickly and effectively was key for both hunting as well as ensnaring a mate for the season.

There was a groan behind him from the human and Dean gave him a cursory glance before slithering from the cave. It was best if Dean gave him a chance to recover from two rounds of mating and Dean hadn’t hunted in a while.

He knew something smaller, from the forest, would be best while breeding the human and then he could get something bigger that would last longer. The camp grounds were always full around this time of the year and adult humans were often distracted enough they didn't keep a good eye on their young offspring. Waiting a few days wouldn’t cost him an easy meal.

Humans were always so eager to bring their offspring to the forest and Dean could easily manage hunting two of them successfully. Two would make a big enough meal to last him through mating season.

* * *

Castiel groaned as he tried to shift on the creature’s nest. Each motion had sharp pains shooting up his back and his ass throbbed. Whenever a spasm of pain lanced through him he couldn’t help but tighten down and that had his abused hole clenching around a huge plug.

He wasn’t sure where the creature had gotten it or even the lube, if it _was_ lube, that he’d used in the beginning.

All he knew was that he needed to somehow get out of there and his body felt like lead. He tried to get his hands under himself to push up but they shook and he found himself belly down once more.

“My luck.” His voice was the only sound in the cave. It was both comforting that creature didn’t appear to be there and depressing because no one would find him. He was alone.

Castiel tried to find a weapon or something to use to defend himself but the closest object that resembled a weapon was across the room. The distance was daunting but he kept attempting to get past the lethargic way his body felt.

Time dragged on and the only thing Castiel accomplished was tiring himself out to the point where he couldn’t keep his eyes open. His body was demanding that he rest and with a whimper he let himself go limp.

Maybe something had killed the creature?

Maybe another hunter had figured it out and intercepted it?

His eyes fluttered and Castiel tried to fight it but eventually sleep overcame him and he slipped into darkness.

But the nightmare followed him.

He dreamed of glowing green eyes and blinding pain accompanied by the creature’s grunts. His mind reminded him of its heavy weight and the feeling of it thrusting both cocks into his pain filled body.

Coming awake was filled with confusion and pain. He blinked and struggled to lift his head up from where it had rested only to realize the weight from his dreams was real. It was pressing him hard into the ground and moving against him. Those grunts were real and the violation slammed into his mind pulling a horrified sound.

Castiel went to put his hands under his body and found they were working far better than before he’d gone to sleep. It had relief crashing through him and he started to actively try to free himself once more.

His actions earned a huff of _amusement_ that had him snarling in anger.

The thrusting slowed but didn’t stop as the creature moved itself and Castiel suddenly found his wrists pinned to the nest he was resting on. It resumed its previous pace only in shorter thrusts and rough rutting.

Castiel struggled to pull in more air as it pressed down on him and suddenly he felt something _twisting_ inside his body. It had pain shooting through him and he slammed his eyes shut as a broken moan of pain escaped him.

His body tensed and he whimpered at the pain in his lower abdomen and his abused rim where he’d unintentionally tightened down. The creature seemed to get excited at the pained noises he was making and Castiel barely noticed when it started stroking his hair while it rocked up into him.

“Mate.” The word slipped free along with the string of words in the creature’s language.

The creature’s release flooded his insides and Castiel could only lay there as it emitted pleased hisses while lazily fucking its two cocks in and out of him.

Finally it pulled out and while Castiel lay there with waves of pain crashing over him it rolled him onto his back. It was the first time he’d seen the creature’s face since it had taken him deeper into the cave.

There was a flush on its cheeks and Castiel could see a hint of blood on its upper body but with no scratches he figured it had killed _something_. He struggled to focus on the creature instead of the pain so he could identify it.

That might help him.

There were emerald scales going up its sides and along its arms. The two cocks were just as large and thick as before, something that horrified Castiel as he knew what they felt like inside him. There were more scales on its legs, its neck and some at its wrists.

A cool hand moved towards him and he flinched. Instead of delivering more pain it stroked over his belly and a string of hisses escaped while its eyes hooded in pleasure. The hand stayed there, stroking, as the pain in his abdomen ebbed and left him limp.

The creature moved closer as it pushed between his legs to stare down at him with hungry and possessive eyes.

He squirmed as its come escaped him and the motion seemed to catch its attention. Castiel watched it reaching for the plug and he frantically shook his head. His stomach was in knots and he had to get up.

“Wait!” he watched it pause and regard him. “I…food?”

It didn’t respond verbally but there was a nod and it climbed to its feet to move across the cave. Castiel tried to get to his feet but the creature whipped around quickly to fix him with an expression that had Castiel slowly lowering himself back down with fear stealing his ability to even think beyond basic instincts.

 

* * *

 

Dean marveled at the swell of his mate’s belly as he lazily fucked into the warm and pliant body under him. It had only taken a few days before he’d managed to breed his mate for the season and now his success was more than obvious.

He enjoyed mating with the human while he was filled with his offspring. As time passed the human had stopped trying to escape and with his pregnancy he was more docile as Dean knew he would be.

It was a way to ensure the safety of the mate carrying and the offspring themselves. The scent coming from the human had his mating drive kicking up randomly and Dean enjoyed pushing himself inside the tight, heat and thrusting.

After so much time with his newest mate he hoped this one survived the first birth. It would give him at least one more breeding season of mating with the blue eyed human. He didn’t expect a human to survive two breeding seasons but he had heard stories of others of his kind keeping one mate for three.

“Oh.” The sound fell from the human’s lips and Dean pressed down against the human wanting closer, still working his hips forward, as he enjoyed the feeling of his cocks brushing against the human’s insides.

He moaned as the pressure inside his body grew and swelled. It had his mouth dropping open and his toes curled at the sensation. Dean relished the rush that came with mating and the little broken sounds his mate released when he pushed his cocks in.

It didn’t matter how many times he mated with the human as his hole was just as tight and perfect as it had been the first time Dean had been able to push inside.

Gradually Dean’s rhythm fell away and he was thrusting wildly chasing his release until it crashed inside him. His whole body tensed, his mouth falling open and his cocks emptied his seed into his pregnant mate.

He came down from the rush of mating and stared down at the swell of the human’s belly. His hands pressed against it. The human would grow larger and larger until he birthed Dean’s offspring. “ _Mine_.” Dean’s fingers trailed over warm skin and he sighed when he felt his children moving.

It was always bittersweet when they eventually grew up and left but he always enjoyed them while they stayed in his cave.

**Author's Note:**

> Don't be shy...I'd love to hear what you thought!
> 
> \---------------
> 
> Prompt was...
> 
> Dean is a monster with 2 dicks looking for a mate to spawn his children. Cas stumbles accidentally into Dean's lair and becomes his prey. 
> 
> Cas can be human or angelic. This can be consensual, dubcon, or noncon.
> 
> I chose the darker theme, noncon, because this prompt was in line with something else I was already writing (which was a very dark idea with dark, dark themes). I just had to tweak a few things and set it up. Just in case anyone is curious WHY I went with noncon!  
> 


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